1 #ifndef __DALI_TOOLKIT_ITEM_LAYOUT_H__
2 #define __DALI_TOOLKIT_ITEM_LAYOUT_H__
5 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <boost/function.hpp>
23 #include <dali/public-api/animation/alpha-functions.h>
24 #include <dali/public-api/common/vector-wrapper.h>
27 #include <dali-toolkit/public-api/enums.h>
28 #include <dali-toolkit/public-api/controls/control.h>
38 typedef IntrusivePtr<ItemLayout> ItemLayoutPtr; ///< Pointer to a Dali::Toolkit::ItemLayout object
40 typedef std::vector<ItemLayoutPtr> ItemLayoutContainer; ///< Container of Dali::Toolkit::ItemLayout objects
41 typedef ItemLayoutContainer::iterator ItemLayoutIter; ///< Iterator for Dali::Toolkit::ItemLayoutContainer
42 typedef ItemLayoutContainer::const_iterator ItemLayoutConstIter; ///< Const Iterator for Dali::Toolkit::ItemLayoutContainer
46 * @brief A support class for managing ranges of items.
51 * @brief Create a range of item identifiers.
53 * @param[in] beginItem The first item within the range.
54 * @param[in] endItem The past-the-end item.
56 ItemRange(unsigned int beginItem, unsigned int endItem)
63 * @brief Copy Constructor.
65 * @param[in] copy ItemRange we should copy from.
67 ItemRange(const ItemRange& copy)
74 * @brief Assignment operator.
76 * @param[in] range The Range to assign from.
77 * @return The updated range.
79 ItemRange& operator=(const ItemRange& range)
87 * @brief Test whether an item is within the range.
89 * @param[in] itemId The item identifier.
90 * @return True if the item is within the range.
92 bool Within(unsigned int itemId)
94 return itemId >= begin &&
99 * @brief Create the intersection of two ranges.
101 * @param[in] second The second range.
102 * @return The intersection.
104 ItemRange Intersection(const ItemRange& second)
106 ItemRange intersection(0u, 0u);
108 // If the ranges intersect
109 if ( (begin < second.end && end > second.begin) ||
110 (second.begin < end && second.end > begin) )
112 intersection.begin = std::max(begin, second.begin);
113 intersection.end = std::min(end, second.end);
119 unsigned int begin; ///< The start of the range
120 unsigned int end; ///< The end of the range
124 * @brief An ItemLayout describes the constraints which are imposed on items in the layout.
126 * - Potentially visible items are represented by Actors, created for ItemView by the ItemFactory.
127 * - Constraints are applied after ItemView activates a layout.
129 * An ItemLayout also describes the direction of input gestures, used to scroll through the layout.
130 * Whilst scrolling, the layout provides a range of items that are within a layout-area (3D bounding volume).
132 class DALI_IMPORT_API ItemLayout : public RefObject
136 /// @brief Function signature of a boolean constraint
137 typedef boost::function<bool (const bool& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> BoolFunction;
139 /// @brief Function signature of a Vector3 constraint
140 typedef boost::function<Vector3 (const Vector3& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> Vector3Function;
142 /// @brief Function signature of a Vector4 constraint
143 typedef boost::function<Vector4 (const Vector4& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> Vector4Function;
145 /// @brief Function signature of a Quaternion constraint
146 typedef boost::function<Quaternion (const Quaternion& current, const float& layoutPosition, const float& scrollSpeed, const Vector3& layoutSize)> QuaternionFunction;
149 * @brief Virtual destructor.
151 DALI_IMPORT_API virtual ~ItemLayout();
154 * @brief Set the orientation of the layout.
156 * @param[in] orientation The orientation of the layout.
158 DALI_IMPORT_API void SetOrientation(ControlOrientation::Type orientation);
161 * @brief Query the orientation of the layout.
163 * @return the orientation of the layout.
165 DALI_IMPORT_API ControlOrientation::Type GetOrientation() const;
168 * @brief Query the minimum valid layout position; this is a negative value.
170 * When scrolling, the first item will move within the range 0 to GetMinimumLayoutPosition().
171 * @param[in] numberOfItems The current number of items in the layout.
172 * @param[in] layoutSize The size of the layout area.
173 * @return The minimum layout position.
175 virtual float GetMinimumLayoutPosition(unsigned int numberOfItems, Vector3 layoutSize) const = 0;
178 * @brief Query the closest anchor position for the given layout position.
180 * This anchor position is the position where all the items in the layout are aligned to
181 * their rounded layout positions in integer.
182 * @param[in] layoutPosition The layout position.
183 * @return The closest anchor position for the given layout position.
185 virtual float GetClosestAnchorPosition(float layoutPosition) const = 0;
188 * @brief Query the layout position for the first item in the layout to move to when the layout
189 * needs to scroll to a particular item.
191 * @param[in] itemId The ID of an item in the layout.
192 * @return The layout position for the first item in the layout to move to.
194 virtual float GetItemScrollToPosition(unsigned int itemId) const = 0;
197 * @brief Query the items within a given layout-area.
199 * @param[in] firstItemPosition The layout-position of the first item in the layout.
200 * @param[in] layoutSize The size of the layout area.
201 * @return The ID of the first & last visible item.
203 virtual ItemRange GetItemsWithinArea(float firstItemPosition, Vector3 layoutSize) const = 0;
206 * @brief Get the closest layout position to bring an item onto the screen.
208 * If the item is already fully on the screen this function will
209 * return the current layout position.
211 * This function is used by systems such as KeyboardFocusManager to
212 * bring the next focusable item into view and all layout
213 * implementations should provide their own version of this function
214 * to ensure proper functionality of internal toolkit systems.
216 * @param[in] itemID id of the item to bring within the viewable screen area
217 * @param[in] currentLayoutPosition the current layout position of the item view instance
218 * @param[in] layoutSize the current size of the item view instance
219 * @return The layout position
221 DALI_IMPORT_API virtual float GetClosestOnScreenLayoutPosition(int itemID, float currentLayoutPosition, const Vector3& layoutSize);
224 * @brief Query the number of items that should be reserved, for scrolling purposes.
226 * @param[in] layoutSize The size of the layout area.
227 * @return The number of extra items. ItemView will populate itself with actors within the layout-area
228 * (see GetItemsWithinArea), plus this number of additional items on either-side.
230 virtual unsigned int GetReserveItemCount(Vector3 layoutSize) const = 0;
233 * @brief Retrieve the target size of an item in the layout.
235 * @note layout-position is not provided as a parameter, since applying size constraints is not recommended.
236 * Animating to target-sizes is preferable, since this allows controls to perform layouting without constraints.
237 * @param[in] itemId The ID of an item in the layout.
238 * @param[in] layoutSize The layout size
239 * @param[out] itemSize The target size of an item, or an uninitialized value.
240 * @return Whether the item size is available or not
242 virtual bool GetItemSize(unsigned int itemId, Vector3 layoutSize, Vector3& itemSize) const = 0;
245 * @brief Retrieve the resize animation in the layout.
247 * @note This allows the layout to provide its own resize animation.
248 * @param[in] animation The resize animation, not owned by the layout
249 * @param[in] actor The actor to animate
250 * @param [in] size The target size.
251 * @param [in] durationSeconds The duration of the resizing.
253 virtual void GetResizeAnimation(Animation& animation, Actor actor, Vector3 size, float durationSeconds) const = 0;
256 * @brief Retrieve the position constraint function of an item in the layout.
258 * The constraint will be applied when the item is created or the layout is activated.
259 * @param[in] itemId The ID of an item in the layout.
260 * @param[out] constraint The position constraint function of an item, or an uninitialized function pointer.
261 * @return Whether the position constraint function of an item is available or not
263 virtual bool GetPositionConstraint(unsigned int itemId, Vector3Function& constraint) const = 0;
266 * @brief Retrieve the rotation constraint function of an item in the layout.
268 * The constraint will be applied when the item is created or the layout is activated.
269 * @param[in] itemId The ID of an item in the layout.
270 * @param[out] constraint The rotation constraint function of an item, or an uninitialized function pointer.
271 * @return Whether the rotation constraint function of an item is available or not
273 virtual bool GetRotationConstraint(unsigned int itemId, QuaternionFunction& constraint) const = 0;
276 * @brief Retrieve the scale constraint function of an item in the layout.
278 * The constraint will be applied when the item is created or the layout is activated.
279 * @param[in] itemId The ID of an item in the layout.
280 * @param[out] constraint The scale constraint function of an item, or an uninitialized function pointer.
281 * @return Whether the scale constraint function of an item is available or not
283 virtual bool GetScaleConstraint(unsigned int itemId, Vector3Function& constraint) const = 0;
286 * @brief Retrieve the color constraint function of an item in the layout.
288 * The constraint will be applied when the item is created or the layout is activated.
289 * @param[in] itemId The ID of an item in the layout.
290 * @param[out] constraint The color constraint function of an item, or an uninitialized function pointer.
291 * @return Whether the color constraint function of an item is available or not
293 virtual bool GetColorConstraint(unsigned int itemId, Vector4Function& constraint) const = 0;
296 * @brief Retrieve the visibility constraint function of an item in the layout.
298 * The constraint will be applied when the item is created or the layout is activated.
299 * @param[in] itemId The ID of an item in the layout.
300 * @param[out] constraint The visibility constraint function of an item, or an uninitialized function pointer.
301 * @return Whether the visibility constraint function of an item is available or not
303 virtual bool GetVisibilityConstraint(unsigned int itemId, BoolFunction& constraint) const = 0;
306 * @brief Query the scroll direction of the layout.
308 * When an input gesture follows this direction, the layout-position of items will be increased.
309 * If the input gesture points in the opposite direction, then the layout-positions will decrease.
310 * @return The scroll direction in degrees.
312 virtual Degree GetScrollDirection() const = 0;
315 * @brief Query the scroll speed factor of the layout while dragging.
317 * This factor is used by the layout to customise its scroll speed while dragging.
318 * The factor will be multiplied with the scroll distance of how many pixels in actor coordinate,
319 * and the layout position of the actors in ItemView will be moved by this result.
320 * For example, when the speed factor is 0.01, if the scroll distance is 100 pixels, the layout
321 * position of actors will be moved by 1.
322 * Therefore, the bigger the factor is, the faster the scroll speed will be.
324 * @return The scroll speed factor of the layout.
326 virtual float GetScrollSpeedFactor() const = 0;
329 * @brief Query the maximum swipe speed in pixels per second.
331 * Swipe gestures will be clamped when exceeding this speed limit.
332 * @return speed The maximum swipe speed.
334 virtual float GetMaximumSwipeSpeed() const = 0;
337 * @brief Get the duration of the flick animation in second.
339 * This is the time taken to animate each
340 * item to its next layout position (e.g. from 1.0 to 2.0) when a flick animation is triggered
341 * by a swipe gesture.
342 * @return The duration of the flick animation.
344 virtual float GetItemFlickAnimationDuration() const = 0;
347 * @brief Gets the id of the next item for KeyboardFocusManager to focus on depending on the inputted item ID.
349 * @param[in] itemID The current focused item
350 * @param[in] maxItems The maximum number of items in the list
351 * @param[in] direction The directional key pressed on the keyboard
352 * @param[in] loopEnabled Whether the KeyboardFocusManager is set to wrap around between first and last item
353 * @return The next item ID.
355 DALI_IMPORT_API virtual int GetNextFocusItemID(int itemID, int maxItems, Dali::Toolkit::Control::KeyboardFocusNavigationDirection direction, bool loopEnabled);
358 * @brief Query the flick speed factor of the layout while swipping.
360 * This factor is used by the layout to customise its scroll speed while swiping.
361 * The factor will be multiplied with the scroll distance of how many pixels in actor coordinate,
362 * and the layout position of the actors in ItemView will be moved by this result.
363 * For example, when the speed factor is 0.01, if the scroll distance is 100 pixels, the layout
364 * position of actors will be moved by 1.
365 * Therefore, the bigger the factor is, the faster the flick speed will be.
367 * @return The scroll speed factor of the layout.
369 DALI_IMPORT_API virtual float GetFlickSpeedFactor() const;
372 * @brief Applies constraints defined by the layout to an actor.
374 * @param[in] actor The actor to constrain.
375 * @param[in] itemId The ID of the item represented by the actor.
376 * @param[in] durationSeconds The time taken to fully constrain the actors.
377 * @param[in] scrollPositionObject The object which provides the layout position property.
378 * @param[in] itemViewActor The item view instance which requests the application of constraints.
380 DALI_IMPORT_API virtual void ApplyConstraints( Actor& actor, const int itemId, const float durationSeconds, Handle scrollPositionObject, const Actor& itemViewActor );
383 * @brief Gets the position of a given item
385 * @param[in] itemID id of the item we want to get its position
386 * @param[in] currentLayoutPosition the current layout position of the item view instance
387 * @param[in] layoutSize the current size of the item view instance
388 * @return The item position (x,y,z)
390 DALI_IMPORT_API virtual Vector3 GetItemPosition(int itemID, float currentLayoutPosition, const Vector3& layoutSize) const;
393 * @brief Set the alpha function used when applying constraints
395 * @param[in] func The alpha function to use.
397 DALI_IMPORT_API void SetAlphaFunction(AlphaFunction func);
400 * @brief Retrieve the alpha function used when applying constraints
402 * @return The alpha function.
404 DALI_IMPORT_API AlphaFunction GetAlphaFunction() const;
409 * @brief Create a new ItemLayout; Only derived versions are instantiatable.
411 DALI_IMPORT_API ItemLayout();
415 ControlOrientation::Type mOrientation; ///< the orientation of the layout.
416 AlphaFunction mAlphaFunction; ///< Alpha function to be applied when removing/adding constraints
417 Handle mWeightObject; ///< Weight object gets created to apply the constraints over a certain time
420 } // namespace Toolkit
424 #endif // __DALI_TOOLKIT_ITEM_LAYOUT_H__